Steven Hobbs, a married Texas father of two charged with killing and assaulting prostitutes for the past decade, may be linked to several other unsolved murders in the area, investigators say.
"We're now going back to 15 years from today to check cold cases," Harris County sheriff's spokesman Alan Bernstein told ABCNews.com. "We're even talking to neighboring counties, which are much more rural, about their cases."
Hobbs, a 40-year-old, 6-foot-4 former security guard, has now been in jail for about two weeks, accused of murdering two women in Harris County and assaulting four others. But he might never have been apprehended if a Pasadena, Texas, motorcycle cop hadn't stopped to set up a routine traffic radar site.
On Sept. 22 the officer pulled over into a brushy area off Red Bluff Road to clock the speed of passing motorists. That's where he discovered what Bernstein described as "the key to everything" -- the badly decomposed body of Wanda Trombley, 57, who had been missing since July.
Her body was "maybe 30 feet from the entrance where Hobbs was [working as] a security guard," said Pasadena Assistant Police Chief Bud Corbett.
Detectives believe the murderer likely dumped Trombley's body in Pasadena because she had worked several miles away in northeast Houston. They began questioning prostitutes in that area.
One of them, a 43-year-old woman whose identity will remain anonymous, told investigators that in June a large white man with "reddish-blond hair and thick eyeglasses" had picked her up to go to a motel for sex, according to the Harris County District Attorney's Office.
But instead of driving to the motel, she said, he brought her to a desolate location on Wallisville Road in Houston, sexually assaulted her at gunpoint, handcuffed her arms and feet and beat her with what appeared to be a mop handle. At some point, she added, he put on a security uniform and spoke to someone on the phone who sounded like an employer.
Two other prostitutes also told detectives they were assaulted by a man fitting Hobbs' description wearing a security uniform.
When detectives showed the 43-year-old victim several mens' photos, she identified Hobbs' picture, saying she was "absolutely certain" that he was the man who had assaulted her.
Hobbs was charged with kidnapping and sexual assault, and also charged with the aggravated assault of 28-year-old prostitute Danielle Perfitt, which also occurred in June.
Investigators filed another charge for the 2010 aggravated assault of 33-year-old prostitute Sandra Gunter.
Meanwhile, detectives at the Harris County Sheriff's Department had been trying to solve other prostitute homicides in the county, and thought Trombley's case sounded similar.
They tested the DNA of the security guards who worked at the business near where Trombley was found.
"The swabs from Steven Hobbs matched DNA evidence at the scene of two murders that took place outside Pasadena but inside Harris County," said Bernstein.
This week, the Harris County District Attorney's office charged Hobbs with strangling prostitute and mother of five Patricia Pyatt, 38, in 2002, and sexually assaulting a woman, whose identity is being protected, that same year. The assault took place near the San Jacinto River, along the Beaumont Highway, not very far from where Pyatt's body was found.
He was also charged with murdering prostitute Sarah Sanford, 48, who was found nude and bound with handcuffs in a wooded area about five miles from Hobbs' home in 2010, according to police. She had been sexually assaulted and shot in the head. DNA from the handcuffs used to bind her, and from her mouth, matched that of Hobbs.
"He's not been cooperating with our detectives," said Bernstein.